Typical electrochemical devices comprise, for example, multiple electrically active layers such as an anode, a cathode, an electrolyte, a substrate and current collectors. Some layers, such as, for example, an anode layer comprising lithium, are comprised of materials that are very environmentally sensitive. The substrate may, for example, not be a separate battery element but instead may be provided by a semiconducting surface or a conductive or insulating packaging surface of a semiconductor device or printed circuit board (PCB) to which the battery is attached. Such batteries require an encapsulation to protect the environmentally sensitive material. Some schemes encapsulate the sensitive layers of electrochemical devices, such as encapsulation with gold foil. Other schemes encapsulate the device with a pouch made of metal and plastic, for example, that seals around the perimeter of the device.
The applicants' earlier filed patents and patent applications provide certain battery and encapsulation designs and techniques, including U.S. Pat. No. 6,916,679 and U.S. Published Patent Applications US 2006/286448 A1, US 2007/184345 A1, US 2007/202395 A1, US 2007/264564 A1, US 2008/261107 A1, US 2008/0286651, and U.S. Patent App Ser. No. 61/179,953, which are herein incorporated by reference in their entirety. These patents and applications provide, for example, types of batteries that, when incorporated with a printed circuit board, may provide a benefit.
Space on the surface of a printed circuit board (PCB), rigid or flexible, is very limited and is thus at a premium. Therefore, there is a need to incorporate electrochemical cells, such as batteries, with the design of PCBs more efficiently, to save and better utilize the PCB surface space.